Front-boom sprayer with a boom center section and lift arm arrangement for improved field of view

ABSTRACT

A front-boom sprayer is provided that includes a boom center section and lift arm arrangement that provides a field of view below the boom when the boom is in a raised state that is substantially free of view obstructions from torque tube or other crosswise-extending components. The lift arm arrangement may provide different link tube geometries so that the respective left and right pairs of upper and lower lift arms align with each other in the line of sight of the in-cab operator.

FIELD OF THE INVENTION

The invention relates generally to agricultural machines includingagricultural product application equipment such as self-propelledsprayers and, in particular, to a front-boom sprayer with a boom centersection and lift arm arrangement that provide an improved field of view.

BACKGROUND OF THE INVENTION

High-clearance sprayers are getting larger and more complex, includingfront boom sprayers with long booms that can be heavy and can applylarge twisting and other loads to the sprayer chassis during use. Inorder to carry the heavy weights and handle the large loads of thebooms, the booms have complex boom attachment systems that include largeboom center sections that are supported by large lift arms, some ofwhich are interconnected by torque tubes. However, in front-boomsprayers, the large boom center sections, lift arms, and torque tubescan compromise the view of the operator. Some previous front-boomsprayers have lift arms without torque tubes, but with upper and lowerlift arms that extend outwardly from their inner ends at connectionpoints to the chassis to their outer ends at the boom center section. Inthese previous front-boom sprayers, the inner ends of the upper liftarms are spaced fairly close to each other, more narrowly than innerends of the lower lift arms. These upper lift arms extended outwardly atfairly sharp angles to their outer ends so that the outer ends of theupper lift arms were spaced farther from each other than outer ends ofthe lower lift arms at the boom center section connection points. Thisprevious arrangement provides wide crisscrossing view blockages of thelift arms from near the centerline of the sprayer outwardly toward outerends of the boom center section. Other previous front-boom sprayers haveparallel and aligned upper and lower lift arms that define parallelogramlinkages with torque tubes that connect the outer ends of the upper liftarms to each other. This previous arrangement provides wide parallelview blockages of the lift arms and a horizontal view blockage from thetorque tube(s), especially at certain boom heights.

SUMMARY OF THE INVENTION

A front-boom sprayer is provided with a boom center section and lift armarrangement for improved field of view compared to, for example, boomlift arms that are connected with torque tubes.

According to one aspect of the invention, upper and lower lift arms havelink tubes that provide different link tube geometries so that therespective left and right pairs of upper and lower lift arms align witheach other in the line of sight of the in-cab operator. This in-cabvisual alignment of the upper and lower lift arms at each of the leftand right sides, along with the torque member adjacent the sprayerchassis instead of a torque tube, provides a substantially unobstructedview through the front of the cab.

According to one aspect of the invention, the lift arm arrangement hasno view-obstructing torque tube. Instead, a torque member is provided bya weldment that may have webbed gussets that interconnect and supplementthe strength of the lower lift arms adjacent the sprayer chassis. Theupper and lower lift arms may have link tubes that provide differentlink tube geometries that define a double partially-triangulated 4-linkhaving different angles with respect to the sprayer's centerline. Ateach of the left and right pairs of lift arms, a triangle may be definedin the top view by the upper and lower lift arm on each side of thesprayer that forms a natural gusset or triangulated stabilizer. Thisimproves the lateral rigidity of the system due to the wider positioningof the lower lift arm outer ends than those of the upper lift arms. Thisconfiguration reduces the need for lateral supports, which lowers costand weight.

According to another aspect of the invention, at the inner ends of thelift arms closest to the sprayer cab, the link tube geometry providesmachine link connection points of the upper and lower lift arms that arevertically aligned as a stack at each of the left and right sides. Atthe outer ends of the lift arms closest to the boom, the link tubegeometry provides vertically misaligned connection points of the upperand lower lift arms at each of the left and right sides. The boom centersection and lift arm outer ends have connection points with the lowerlift arms spaced farther from each other than the connection points ofthe upper lift arms. In this way, the upper lift arms extend closer toparallel to the centerline of the sprayer and the lower lift arms extendat greater angles with respect to the sprayer centerline. The differentlink tube geometries may be provided with arm ends that are commoncastings, which provide fewer parts to inventory. Cutting the link tubeends that connect to the arm ends at different angles provides thedifferent overall geometry of the upper and lower lift arms even thoughcommon casting arm ends are used. As one example, the lower link tubescan be cut straight or perpendicular and, the top link tubes can be cutat angles so that the upper and lower arms define different angles withrespect to the sprayer centerline.

According to another aspect of the invention, the upper and lower liftarms can be made slightly different lengths (in the side view) to notonly compensate for droop due to the side loading of the non-planerparallel linkage, but also allow a different height for the end of theprimary when folded than when deployed. This could be arranged such thatthe wing or boom arm can rise high in the operating position, but notovershoot the saddle of a boom rest when folded.

According to another aspect of the invention, an angled plate connectsthe lower lift arms to each other as a segment of a weldment thatdefines the torque member and also provides a crop deflector that actsas a transition to the sprayer's belly pan.

According to another aspect of the invention, a boom center section hasa left end for supporting a left boom arm and a right end for supportinga right boom arm. The boom center section may include a cross-memberthat defines cross-member left and right ends and extends transverselywith respect to a centerline of the sprayer. Left and right boom armmounts are arranged at the center section left and right ends and areconfigured to support the left and right boom arms. The left and rightboom arm mounts extend downwardly from the cross-member left and rightends. The boom center section may define an upside down U-shaped bodywith an open lower end that is defined below a center sectioncross-member lower edge and between the left and right boom mounts thatextend downwardly cross-member. A lift arm arrangement connects thesprayer boom to the chassis front end. The lift arm arrangement includesa pair of upper lift arms, such as a left and right upper lift arm withan outer end connected to the cross-member left end and a right upperlift arm with an outer end connected to the cross-member right end. Theleft and right upper lift arms are spaced from each other by a firstdistance. A pair of lower lift arms includes left and right lower liftarms with outer ends that are connected to the cross-member right end.The outer ends of the left and right lower lift arms are spaced fromeach other by a second distance that is greater than the first distance.When the boom is in a raised position with the boom center section abovean eye level of an operator in a cab of the sprayer, an under-boomfield-of-view window is defined as an opening that is bounded from aboveby the lower edge of the center section cross-member and at leastpartially bounded at left and right sides by the inner edges of the leftand right boom mounts.

According to another aspect of invention, a torque member is providedthat may include a torque member plate that extends between inner endsof the left and right lower lift arms. The torque member may define aU-shaped body that may include curved gussets that provide at least partof a lower boundary to the under-boom field-of-view window.

According to another aspect of the invention, a pair of chassis lift armmounts are provided at the chassis front end for connecting the innerends of the upper and lower lift arms to the chassis front end. Eachchassis lift arm mount may include an upper lift arm receiver and alower lift arm receiver that accepts an inner end of a respective upperand lower lift arm and wherein the upper and lower lift arm receivers ateach lift arm mount are vertically aligned with each other and the upperand lower lift arms may extend from the upper and lower lift armreceivers at different angles. The lower lift arms may extend at agreater angle with respect to a sprayer centerline than the upper liftarms. Each of the link arms may include a link tube and an arm end ateach of their inner and outer ends. The arm ends may be a commoncomponent or have a common configuration with respect to the other armends. The arm ends may be angled from inner ends that are attached tothe link tubes to outer ends that are attached to the boom centersection or the chassis lift arm mount. The ends of the upper and lowerlink tubes may be cut to different angles for attaching to the arm ends.When viewed from above, the ends of the lower lift arm link tubes may beperpendicular with respect to a longitudinal axis of the link tube ofthe lower lift arms and the ends of the upper lift arm link tubes may beangled.

According to another aspect of the invention, the torque member mayinclude side plates that extend from the inner ends of the lower liftarms to their outer ends. The side plates may be generally triangularand taper downwardly from the inner ends of the lower lift arms to theirouter ends.

Other aspects, objects, features, and advantages of the invention willbecome apparent to those skilled in the art from the following detaileddescription and accompanying drawings. It should be understood, however,that the detailed description and specific examples, while indicatingpreferred embodiments of the present invention, are given by way ofillustration and not of limitation. Many changes and modifications maybe made within the scope of the present invention without departing fromthe spirit thereof, and the invention includes all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred exemplary embodiments of the invention are illustrated in theaccompanying drawings in which like reference numerals represent likeparts throughout.

FIG. 1 is an isometric view of a front-boom sprayer with a boom centersection and lift arm arrangement for improved field of view inaccordance with the present invention;

FIG. 2 is an isometric view of a portion of the sprayer on FIG. 1;

FIG. 3 is top plan view of portions of the sprayer of FIG. 1;

FIG. 4 is side elevation view of portions of the sprayer of FIG. 1;

FIG. 5 is an enlarged isometric view of a portion of the lift armarrangement of FIG. 1;

FIG. 6 is another enlarged isometric view of a portion of the lift armarrangement of FIG. 1;

FIG. 7 is a front elevation view of a portion of the sprayer of FIG. 1;and

FIG. 8 is an elevation view looking forward under a boom from inside thecab of the sprayer of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and specifically to FIG. 1, aspects of theinvention are shown for use with an agricultural machine which could bean agricultural sprayer. The agricultural sprayer is shown here as aself-propelled agricultural sprayer vehicle or self-propelled sprayer10. Sprayer 10 is shown as a front-boom sprayer, such as those availablefrom CNH Industrial, including the Miller Nitro sprayers and New HollandGuardian Series sprayers.

Still referring to FIG. 1, sprayer 10 includes a chassis 12 having frontand back ends and a chassis frame that supports various assemblies,systems, and components. These various assemblies, systems, andcomponents can include an operator cab 16 in a forward position towardthe front end of the chassis 12 and sprayer 10. Engine 18 and ahydraulic system 20 are shown in a rearward position toward the back endof the sprayer chassis 12. The hydraulic system 20 receives power fromthe engine 18 and includes at least one hydraulic pump which can be in ahydrostat arrangement for providing hydraulic pressure for operatinghydraulic components within the hydraulic system 20. For sprayers withhydrostatic drives, hydraulic motors are operably connected to thehydraulic pump(s) for rotating the wheels 22. In mechanical driveapplications, a mechanical transmission receives power from the engine18 and delivers power for rotating the wheels 22 by way ofpower-transmitting driveline components such as drive shafts,differentials, and other gear sets in portal, drop boxes, or otherhousings. A spray system or application system 24 is supported by thechassis 12 and can include storage containers such as a rinse tank forstoring water or a rinsing solution and a product tank 28 for storing avolume of product for delivery onto an agricultural field with sprayer10. A product delivery pump can convey product from the product tank 28through plumbing components such as interconnected pieces of tubing andthrough a boom tubing system for release out of spray nozzles that arespaced from each other along the width of boom 30 during sprayingoperations of sprayer 10. Groups or banks of multiple adjacent spraynozzles define multiple spray sections of the spray system. Spraysections are defined along boom 30 and selectively deliver product forrelease onto an agricultural field at locations corresponding topositions of activated spray sections. Boom 30 is connected to chassis12 with a lift arm assembly or arrangement 32 that is attached to a boomcenter section 34 and is configured to move the boom 30 up and down foradjusting the height of application of the product. Boom 30 has multipleinterconnected boom segments that collectively define each of a left andright boom arm 30 a, 30 b that extend in opposite directions from a boomcenter section 34 that is carried by the lift arm arrangement 32. Theboom segments of the left and right boom arms 30 a, 30 b are configuredalong with corresponding actuators to allow the boom 30 to fold into atransport position or extend out into it as an in-use or spray position.

Referring not to FIGS. 1 and 2, boom center section 34 has first andsecond ends, shown here as a left end 36 for supporting a left boom armand a right end 38 for supporting a right boom arm. The boom centersection 34 has a cross-member 40 that extends transversely with respectto a centerline of the sprayer and defines cross-member left and rightends 42, 44. Left and right boom arm mounts 46, 48 are arranged at thecenter section left and right ends 36, 38 and are configured to supportthe left and right boom arms 30 a, 30 b. The left and right boom armmounts 46, 48 extend downwardly from the cross-member left and rightends 42, 44 and have generally vertical outer walls at which the jointsare arranged for it mounting the left and right boom arms 30 a, 30 b.Each of the boom arm mounts 46, 48 has a generally triangular body thatis wider toward its top portion at the cross-member 40 and tapersdownwardly toward its lower portion. As shown in FIG. 2, this gives thecenter section 34 an upside down U-shaped body with a lower recessdefined by a perimeter with a raised upper perimeter wall segment thatis defined by a lower edge of the center section cross-member 40 andside perimeter wall segments that are defined by inner edges of the leftand right boom mounts 46, 48 that extend downwardly, shown extendingdownwardly and outwardly at an angle, from the upper perimeter wallsegment at the lower edge of cross-member 40.

Referring now to FIGS. 3-4, the lift arm arrangement includes a pair ofupper lift arms 50, such as left and right upper lift arms 50 a, 50 b(FIG. 3), with outer ends 52 connected to the cross-member left andright ends 42, 44 and inner ends 54 connected to the front end ofsprayer chassis 12 (FIG. 1). Each upper lift arm 50 has a link tube 56with outer and inner ends arranged at the lift arm outer and inner ends52, 54. A pair of lower lift arms 60, such as left and right lower liftarms 60 a, 60 b (FIG. 3), with outer ends 62 connected to thecross-member left and right ends 42, 44 and inner ends 64 connected tothe front end of sprayer chassis 12 (FIG. 1). Each lower lift arm 60 hasa link tube 66 with outer and inner ends arranged at the lift arm outerand inner ends 62, 64. Arm ends 70 are attached to the ends of the linktubes 56, 66 of the upper and lower lift arms 50, 60, such as bywelding, and provides the features such as an end knuckle with a borefor connecting the lift arms 50, 60 to the corresponding mountingcomponents of the sprayer chassis 12 and center section 34. Arm ends 70are shown as common components with the same configuration, such as asingle inventoried part. As seen in FIG. 3, each arm end 70 has a firstside wall, such as an inside side wall, that extends along a straightline path and a second side wall, such as an outside side wall, that issegmented with these segments extending angularly with respect to eachother. Arm end 70 has a back or inner wall that is angled with respectto a bore that extends through a knuckle at a forward or outer end ofarm end 70.

Referring now to FIG. 3, even though the arm ends 70 are the same forall of the upper and lower lift arms 50, 60, the upper and lower liftarms 50, 60 extend at different angles with respect to each otherrelative to a centerline 72 of sprayer 10. This may be achieved bycutting ends of the link tubes 56, 66 of upper and lower lift arms 50,60 at different angles before attaching the arm ends 70. Lower lift arm60 extends at greater angles with respect to the sprayer centerline 72than the upper lift arms 50. The end of the upper lift arm link tube(s)56 is cut to an angled end when viewed from above, which provides arelatively lesser angle between a longitudinal axis of the upper liftarm link tube 56 with respect to a bore that runs through the knuckle atthe outer end of arm end 70. That is because the angles of the cutend(s) of upper lift arm 56 and the angled back wall of arm end 70 arearranged with respect to each other to lessen the overall angle definedbetween longitudinal axis of the upper lift arm link tube 56 withrespect to the board that runs through the knuckle at the outer end ofarm end 70. The end of the lower lift arm link tube(s) 66 is cut to aperpendicular end when viewed from above, which provides a relativelygreater angle between a longitudinal axis of the lower lift arm linktube 66 with respect to a bore that runs through the knuckle at theouter end of arm end 70, which corresponds to the angle between the backwall of arm end 70 relative to the bore through the knuckle at the outerend of arm end 70.

Still referring to FIG. 3, at each side of the lift arm arrangement 32,the outer ends 52, 62 of the respective upper and lower lift arms 50, 60are vertically staggered or misaligned with each other at theirattention points to the boom center section 34. Also, at each side ofthe lift arm arrangement 32, the inner ends 54, 64 of the respectiveupper and lower lift arm 50, 60 are vertically stacked or aligned witheach other at their attention points to the front end of sprayer chassis12 (FIG. 2).

Referring now to FIGS. 5-6, center section lift arm mounts 80 arearranged at each side of the center section left and right ends 36, 38.Each lift arm mount 80 has a bracket 82 that extends from a rearwardfacing surface of the respective boom arm mount(s) 46, 48 and has a pairof bracket side walls 84 that define a space between them which receivesthe arm end 70. The bracket 82 of each lift arm mount 80 is configuredto pivot mount the respective arm end 70 about a pin that extendsthrough the sidewalls 84 and the bore of the knuckle at the outer end ofarm end 70. The pins in the lift upper and lower arm mounts 80 at eachside of the center section 34 extend parallel to each other and arevertically and horizontally staggered with respect to each other toattach the outer ends of upper and lower lift arms 50, 60 to the centersection 34.

Referring now to FIG. 2, inner ends of upper and lower lift arms 50, 60are attached to the front end of sprayer chassis 12 (FIG. 1) withchassis lift arm mounts 90. Chassis lift arm mounts 90 are arranged ateach side of the chassis 12 (FIG. 1) and may be provided by integral orconnected components to the chassis frame. Each lift arm mount 90 has abracket 92 that extends from a forward facing end of the chassis(FIG. 1) and has a pair of bracket side walls 94 that define a spacebetween them which receives the arm end 70. The mounting arrangement ofeach arm end 70 within the bracket 92 defines a lift arm receiver 96that is configured to pivot mount the respective arm end 70 about a pinthat extends through the sidewalls 94 and the bore of the knuckle at theouter end of arm end 70. The pins in the lift arm receiver(s) 96 at eachside of the center section 34 extend parallel to each other and arevertically aligned or stacked with respect to each other to attach theouter ends of upper and lower lift arms 50, 60 to the center section 34along a common vertical plane. With the arm ends 70 in each receiver 96of bracket 92 directly vertically aligned with each other, the arm end70 segments of the upper and lower lift arms 50, 60 may entirely overlapeach other while the remainder of the upper and lower lift arms 50, 60may slightly diverge from each other while extending toward the centersection 34 based on the different angles of the ends (FIG. 3) of thecorresponding link tubes 56, 66 (FIG. 4). A lift arm stop may bearranged in each of the brackets 92, shown here (but not labeled) withfirst and second perpendicularly arranged walls to respectively limitthe lower and upper pivot movements of the upper and lower lift arms 50,60.

Referring again to FIGS. 3-4, a torque member 100 may be defined by aweldment(s) that connects the left and right lower lift arms 60 a, 60 bto each other, which improves rigidity of the lift arm arrangement 32.Torque member 100 includes a torque member plate 102 that extendsbetween inner ends 64 of the lower lift arms 60. As shown in FIG. 4,torque member plate 102 may define an angled lower plate of the torquemember 100 that provides a crop deflector that acts as a crop deflectingramp or other transition to the sprayer's belly pan. Side plates 104extend from the inner to outer ends 64, 62 of the lower lift arms 60.Side plates 104 are shown here with generally triangular perimetershapes that taper down from a greater height at the inner ends 64 of thelower lift arms 60 to a shorter height at the outer ends 62 of the lowerlift arms 60. At the inner end 64, side plate(s) 104 may extend belowthe chassis lift arm mount(s) 90 and provide a lobe 106. The lobe 106may have a pair of spaced apart walls, with the second wall behind theillustrated surface and not visible in this view, to provide a bracketor yoke-like configuration, for connecting the lift arm arrangement 32to an actuator such as a hydraulic cylinder for moving the lift arms 50,60 up and down to change the height of boom 30 (FIG. 1). Advancing thepiston out of the hydraulic cylinder pushes the lobe 106 forward andpivots it about the connection between the lower lift arms 60 andchassis lift arm mount 90 to drive the lift arms 50, 60 to pivotupwardly and raise the boom 30 (FIG. 1). Retracting the piston into thehydraulic cylinder pulls the lobe 106 rearward and pivots it in theopposite direction about the connection between the lower lift arms 60and chassis lift arm mount 90 to drive the lift arms 50, 60 to pivotdownwardly and lower the boom 30 (FIG. 1).

As shown in FIG. 3, when viewed from above, torque member 100 may definea U-shaped body 110 with an upper recess defined by a perimeter with alower perimeter wall segment that is defined by an outer edge of thetorque member plate 102, and side perimeter wall segments are defined atleast in part by respective side walls of the lower lift arms 60. Webbedgussets 112 may further define the U-shaped body by providing curvedtransitions between the lower lift arms 60 and the torque member plate102, when viewed from above. In this way, the U-shaped profile providedby the torque member 100 is arranged generally horizontally and tilts ormoves with movement of the lower lift arms 60 and boom 30 (FIG. 1),whereas the upside down U-shaped profile provided by the center section34 is arranged generally vertically and substantially maintains thisorientation during movement of the lower lift arms 60 and boom 30 (FIG.1).

Referring now to FIG. 7, this is a simplified schematic representationas an example of an improved field of view that is provided by the boomcenter section 34 and lift arm arrangement 32 when the boom is in araised position, such as with the center section 34 above eye level ofthe operator. An under-boom field-of-view window is represented aswindow 120 that is defined as an opening that is bounded by structuresof lift arm arrangement 32 and boom center section 34. The under-boomview window 120 is a continuously open space that extends verticallyfrom an upper surface of the torque member 100 to a lower surface of theboom center section 34 and horizontally between the lift arms 50, 60 atthe left and right sides of lift arm arrangement 32.

Referring now to FIG. 8, from inside the cab 16, at each of the left andright sides of the lift arm arrangement 32, the respective pair(s) ofupper and lower lift arms 50, 60 are substantially align with each otherand align with left and right A-pillars 130 of the cab 16 that extendfrom the cab's floor to roof and may support, for example, mirrors, doorhinges or other cab components. As shown, when the boom 30 is in itsraised position, from inside the cab 16, upper lift arms 50 appeared toextend substantially vertically straight up, parallel to and adjacent toA-pillars 130. Lower lift arms 60 are visually overlapped by the upperlift arms 50 and A-pillars 130. This arrangement collects all of thepotentially view obstructing components of boom and boom supportcomponents into a single view columnar potential view obstruction orblocked zone 140 at each side of the cab 16. Such components areoverlapped or stacked with respect to each other and with respect to theA-pillars within the operator's line of sight, which provides a visuallyoverlapping stacked arrangement within zone 140 and less viewobstruction than if the lift arms were parallel to each other orcrisscross-overlapped each other. This reduces the width of such zone140 and provides a wide field of view(s) out of the cab 16 that, alongthe height of the field of view, has an open viewable width in whichboom-support components are transversely spaced from each other withinthe field of view by about the same width as the width between the cabA-pillars themselves, such as, for example, at least about ⅔ of the orgreater of the width of the space between the A-pillars. The outwardlyangled arrangement of the upper and lower lift arms 50, 60, with thewider spacing between the lower the arm 60 than the upper lift arms 50,provides an expanded viewable field from an operator seat in the cab 16.As shown in FIG. 8, this arrangement give the under-boom view window 120a substantially rectangular shape with vertical walls that align withthe cab A-pillars and rounded corners, with an inside space that iscontinuously open or free of major boom load-supporting structures sothat a straight-ahead view of the operator is substantiallyunobstructed.

Although the best mode contemplated by the inventors of carrying out thepresent invention is disclosed above, practice of the above invention isnot limited thereto. It will be manifest that various additions,modifications, and rearrangements of the features of the presentinvention may be made without deviating from the spirit and the scope ofthe underlying inventive concept.

We claim:
 1. A front-boom sprayer with a boom center section and liftarm arrangement for improved field of view, the front-boom sprayer,comprising: a chassis that defines a front end and has wheels for movingthe front-boom sprayer; an application system supported by the chassisand including at least one product tank storing a volume of agriculturalproduct for delivery onto an agricultural field; a sprayer boomconfigured to deliver the volume of agricultural product to theagricultural field, the sprayer boom including, left and right boomarms; a boom center section with a left end for supporting the left boomarm and a right end for supporting the right boom arm, wherein the boomcenter section includes, a cross-member that defines cross-member leftand right ends and extends transversely with respect to a centerline ofthe sprayer boom; and left and right boom arm mounts arranged at thecenter section left and right ends and configured to support the leftand right boom arms, wherein the left and right boom arm mounts extenddownwardly from the cross-member left and right ends; a lift armarrangement that connects the sprayer boom to the chassis front end andincludes, a pair of upper lift arms including a left upper lift arm withan outer end connected to the cross-member left end and a right upperlift arm with an outer end connected to the cross-member right end,wherein the outer ends of the left and right upper lift arms are spacedfrom each other by a first distance; a pair of lower lift arms includinga left lower lift arm with an outer end connected to the cross-memberleft end and a right lower lift arm with an outer end connected to thecross-member right end; wherein the outer ends of the left and rightlower lift arms are spaced from each other by a second distance that isgreater than the first distance.
 2. The front-boom sprayer of claim 1,wherein the boom center section defines an upside down U-shaped bodywith a lower recess defined by a perimeter with a raised upper perimeterwall segment that is defined by a lower edge of the center sectioncross-member and side perimeter wall segments that are defined by inneredges of the left and right boom mounts that extend downwardly from theupper perimeter wall segment.
 3. The front-boom sprayer of claim 2,wherein when the boom is in a raised position with the boom centersection above an eye level of an operator in a cab of the front-boomsprayer, an under-boom field-of-view window is defined as an openingthat is bounded from above by the lower edge of the center sectioncross-member and at least partially bounded at left and right sides bythe inner edges of the left and right boom mounts.
 4. The front-boomsprayer of claim 1, further comprising a torque member including atorque member plate that extends between inner ends of the left andright lower lift arms.
 5. The front-boom sprayer of claim 4, wherein thetorque member defines a U-shaped body with an upper recess defined by aperimeter with a lower perimeter wall segment that is defined by anouter edge of the torque member plate and side perimeter wall segmentsare defined at least in part by respective side walls of the lower liftarms.
 6. The front-boom sprayer of claim 5, wherein when the boom is ina raised position with the boom center section above an eye level of anoperator in a cab of the sprayer, an under-boom field-of-view window isdefined as an opening that is bounded from below by the outer edge ofthe torque member plate and at least partially bounded at left and rightsides by the respective side walk of the lower lift arms.
 7. Thefront-boom sprayer of claim 1, further comprising a pair of chassis liftarm mounts at the chassis front end for connecting the inner ends of theupper and lower lift arms to the chassis front end.
 8. The front-boomsprayer of claim 7, wherein each chassis lift arm mount includes anupper lift arm receiver and a lower lift arm receiver that accepts aninner end of a respective upper and lower lift arm and wherein the upperand lower lift arm receivers at each lift arm mount are verticallyaligned with each other.
 9. The front-boom sprayer of claim 8, whereinat each lift arm mount, the upper and lower lift arms extend from theupper and lower lift arm receivers at different angles.
 10. Thefront-boom sprayer of claim 9, wherein the lower lift arms extend at agreater angle with respect to the centerline of the sprayer boom thanthe upper lift arms.
 11. The front-boom sprayer of claim 10, whereineach of the upper and lower link arms comprises a link tube and an armend at each of the inner and outer ends of the link arms and whereineach of the arm ends has a common configuration with respect to theother arm ends of the upper and lower lift arms.
 12. The front-boomsprayer of claim 11, wherein the arm ends each has an angled inner endthat is configured to attach to a respect end of the link tube.
 13. Thefront boom sprayer of claim 12, wherein the ends of the link tubes ofthe upper and lower lift arms define different angles at respective endsurfaces.
 14. The front-boom sprayer of claim 13, wherein the ends ofeach of the link tubes of the upper lift arms are angled with respect toa longitudinal axis of the link tube when viewed from a top plan viewand wherein the ends of each of the link tubes of the lower lift arms isperpendicular with respect to a longitudinal axis of the link tube ofthe lower lift arms.
 15. The front-boom sprayer of claim 1, furthercomprising a torque member including, a torque member plate that extendsbetween inner ends of the left and right lower lift arms and angularlywhen viewed from a side elevation; and a torque member top gusset thatextends from and interconnects the torque member plate with the lowerlift arms.
 16. The front-boom sprayer of claim 15, further comprisingtorque member side plates that extend from the inner ends of the lowerlift arms to the outer ends of the lower lift arms, and wherein thetorque member side plates taper down from a greater height at the innerends of the lower lift arms to a shorter height at the outer ends of thelower lift arms.